In Fayette County, Strickland received 70.45 percent of the vote in the Democratic primary. Sittenfeld received 19.09 percent and Prather received 10.46 percent, according to unofficial totals from the Fayette County Board of Elections.

The Democratic effort to unseat Portman already has generated a hotly contested race that could prove pivotal to the party’s hopes of winning back control of the Senate. Strickland enjoyed the state Democratic party leadership’s backing in his primary, but Sittenfeld resisted calls for drop his upset bid.

Portman handily won his primary against Don Elijah Eckhart, a former legislative service commission employee in the Columbus area. The Cincinnati area incumbent seeking a second term had 82 percent of the vote to 16 percent for Eckhart with 28 percent of precincts reporting.

In Fayette County, Portman received over 85 percent of the vote, according to unofficial totals.

Open U.S. House seats have become rare in Ohio, so former Speaker John Boehner’s resignation from Congress last year touched off a free-for-all to succeed him. Eighth House District Republicans in western Ohio sorted through 15 candidates in dual races for nominations to complete Boehner’s term and for the next Congress, and no candidate was able to pull away in early returns.

For most of the Senate campaign, Strickland, 74, avoided joint appearances with Sittenfeld, 31, while looking ahead to the general election with Portman. At an editorial board meeting in Cleveland, he said he had been going around the state, denying that he had been “a ghost candidate” in hiding. Sittenfeld challenged him to a series of debates, but Strickland said he didn’t think he needed to give Sittenfeld a platform.

Sittenfeld won support from another former Democratic governor, Dick Celeste, and some state newspapers were critical of Strickland’s refusal to debate. He also got celebrity support from Star Wars actor Mark Hamill and “Breaking Bad” tough guy Jonathan Banks. While Sittenfeld criticized Strickland for his usually NRA-friendly record, Strickland gained a late endorsement from former U.S. Rep. Gabby Giffords, the anti-gun violence advocate who was shot while she was a congresswoman.

President Barack Obama and Vice President Joe Biden this month announced their backing of Strickland, and in another example of looking ahead, the Strickland campaign scheduled a post-primary March 22 fundraiser in Cincinnati with Biden.

Portman’s campaign was also anticipating a race with Strickland as he sought a second term. It went immediately on the attack against “Retread Ted,” who was turned out by Ohio voters in favor of Gov. John Kasich in 2010.